An ion with mass number `56` contains `3` units of positive charge and `30.4%` more neutrons then electrons. Assign the symbol to this ion.

Explanation

To solve the problem, we need to find the symbol of the ion based on the given information. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Given Information
We know that:
- The mass number (A) of the ion is 56.
- The ion has a charge of +3, which means it has 3 more protons than electrons.
- The number of neutrons is 30.4% more than the number of electrons.

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